Cheaper than solar: How lifting a weight can light up the world

Two British inventors' low cost lamp powered by gravity promises to bring light to rural communities and wean them off the pollutive and costly kerosene lamps.

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British inventors Martin Riddiford and Jim Reeves have developed a promising revolutionary product that will provide light to rural and poor communities at a price cheaper than solar.

Their low-cost LED lamp, GravityLight, is powered by the movement of weights. Users can hang anything - a few pieces of rock to a bag of sand - weighing seven of 12 kilogrammes on the lamp to power it. The lamp produces only 0.1W of power or a deciwatt, but this is sufficient to give light.

Deciwatt, the company Riddiford and Reeves set up to manufacture GravityLight, is currently testing the product and has sent hundreds of samples of the product for field trials in at least 25 countries around the world - especially on off-grid communities - at a cost of US$10.

Riddiford and Reeves initially created the lamp for charity organisation Solar Aid, which called for ideas on developing a low-cost LED lantern as a viable alternative to kerosene lamps.

Kerosene lamps are fuelled by kerosene, a fossil fuel by-product, and is widely used as a lighting sourceby many rural communities that do not have electricity and are not connected to the electric grid.

Given the costs associated with developing portable solar lighting, which include batteries, Riddiford and Reeves said they created the productbased on what is easily available for people in these communities.

By harnessing the power of weights and gravity, they have come up with a mechanical solution that is also an affordable, sustainable and reliable source of light. It does not require sunlight or batteries and incur no operational costs.

Through a crowdfunding campaign with United States based fund-raising social enterprise indiegogo, Deciwatt was able to raise funds of almost US$400,000 in January last year. This exceeded their goal of $55,000, which would enable them to continue the project and produce it for the off-grid communities in Africa and Asia.

Deciwatt said it aims to bring the product to a wider market by 2015. They hope that through mass production, the cost of the product can be reduced further to US$6-7.